Beam and Top Chord Extensions

[Scott Wilson]

Anyone know why beam and joist top chord extensions don't show up in plan at a coarse detail level? They render just fine in 3D and show up in plan with a medium detail level. Images attached...

SW

[Tom Weir]

Hi,
When I looked at the K-series family I could not find a stick symbol constrained to the extents of the joist (including the top chord extension). If it 's there it is not constrained to the chord extension but rather to the support points.

So I added in a stick symbol (structural framing projection), and now it seems to show the extension. I have included that here for you to check out. You should be able to do the same with the other joist families if you need to.

It seems like the family should show the extension, as you indicate.

Tom Weir
Los Angeles

[Scott Wilson]

Thanks, Tom....

There does seem to be a flaw in how these families work. Your solution works okay for me, but it would be nice to not have the gap at the support. There doesn't look to me to be a way to handle this in the family. Thanks.

SW

[Scott Wilson]

OK, I think I figured it out. I took the stick symbol and assigned some additional parameters and an IF function to produce the correct graphics. Kind of a messy workaround, but it works.

SW

[Tom Weir]

SW,
Good Job... I wasn't getting that gap when I did it. Glad you had the wherewithal to figure a workaround. I think that the basic family should have a swtich to show that extension or not. I think we should pout this into the wish-list area.

Tom

[Scott Wilson]

I just noticed that it won't work for sloped joists, though. The extensions still won't show up in plan. I'm fresh out of ideas.

[Tom Dorner]

As a Revit Building user I was asked to take a look at the problem identified by this post for our internal RS4 use.

I was able to add some parameters to control the top chord offsets (I called them A & B) and control the visibility of those offsets in course stick view.

I also added a Parameter that askes if you want the extension to be equal and if so takes the Uniform extension parameter and applies it to both extensions. There does seem to be more of a time lag when using this version with these parameters rather than the OOTB Revit K Joist family.

Since I have not built any structural models in Revit, is this performance hit a problem?

Any feedback on this issue would be appreaciated.

[Troy.DeGroot]

Scott,
Does your work around do anything for the section cut or is it just a band-aid for the plan stick figure. Also, I am new to Revit, what do I do with the file you attached? Sorry if this is a dumb question I am on my first project.

[rmcelvain.103137]

Troy,

Here is a Revit Structure 4 family that I modified. I added functionality for top chord and bottom chord extensions.

Check out the additional instance parameters, they'll control the symbolic line representation (coarse detail level). If you don't understand something about it I can try to explain it further.

FYI, the parameter for the bottom chord extension is measured from the end bearing point.

Hope it helps!

[Scott Wilson]

Troy -

The family does extend both the actual top chord and stick symbol. I haven't spent any more time trying to resolve what happens with sloped joists. Maybe the other posted families can handle it.